The present invention relates to an autostereoscopic display apparatus comprising an image display device for providing a display output composed of rows and columns of pixels and a lenticular means comprising an array of lenticular elements for directing the outputs from respective groups of pixels in mutually different directions so as to enable a stereoscopic image to be perceived.
Examples of such autostereoscopic display apparatus are described in the paper by C. van Berkel et al entitled "Multiview 3D--LCD" published in SPIE Proceedings Vol. 2653, 1996, pages 32 to 39 and in GB-A-2196166. In these examples the display device comprises a matrix LC (liquid crystal) display panel which has rows and columns of pixels (display elements) and which acts as a spatial light modulator to modulate light directed therethrough from a light source. The display panel can be of the kind used in other display applications, for example computer display screens for presenting display information in two dimensional form. A lenticular sheet, for example in the form of a molded or machined sheet of polymer material, overlies the output side of the display panel with its lenticular elements, comprising (semi) cylindrical lens elements, extending in the column direction with each lenticular element being associated with a respective group of two, or more, adjacent columns of display elements and extending parallel with the display element columns. In an arrangement in which each lenticular is associated with two columns of display elements, the display panel is driven to display a composite image comprising two 2D sub-images vertically interleaved, with alternate columns of display elements displaying the two images, and the display elements in each column providing a vertical slice of the respective 2D (sub) image. The lenticular sheet directs these two slices, and corresponding slices from the display element columns associated with the other lenticules, to the left and right eyes respectively of a viewer in front of the sheet so that, with the sub-images having appropriate binocular disparity, the viewer perceives a single stereoscopic image. In other, multi-view, arrangements, in which each lenticule is associated with a group of more than two adjacent display elements in the row direction and corresponding columns of display elements in each group are arranged appropriately to provide a vertical slice from a respective 2-D (sub-) image, then as a viewer's head moves a series of successive, different, stereoscopic views are perceived for creating, for example, a look-around impression. In view of the need for the lenticular elements to be accurately aligned with the display pixels, it is customary for the lenticular screen to be mounted over the display panel in a permanent manner so that the position of the lenticular elements is fixed in relation to the array of pixels.
Autostereoscopic display apparatus of this kind can be used for various applications, for example in medical imaging, virtual reality, games and CAD fields.